Clinical studies of the relationship between infection and wheezing are being pursued. A longitudinal study of lower respiratory tract infections in the first three years of life and its relation to the development of allergy or asthma is in its second year. A study of the microbial agents involved in status asthmaticus and a double blind trial of antibiotics or placebo in that disease has been begun. Laboratory investigation of respiratory viral infection includes a study of the neutralizing antibody developing after respiratory syncytial virus infection and new methods of measuring secretory to viruses.